When two parallel lines are intersected by a third line — a transversal — corresponding pairs of angles are formed. You can use the properties of these angles to find missing angles.
Practice questions
Use the figures and the given information to solve for the missing angles in the following questions.

as shown in the following figure.
If

as shown in the following figure.
If
Answers and explanations
80 degrees
When two parallel lines are cut by a transversal, corresponding angles are formed.
are corresponding angles, so they're congruent:
The three angles of
add up to 180 degrees, so
35 degrees
are supplementary, which means they add up to 180 degrees:
form a straight line, so they also add up to 180 degrees: